1- Download the extension from here
2- Unzip the extension
3- Open Edge Extensions or simply go Go to edge://extensions
3- Enable Developer Mode
4- Click on Load Unpacked
5- Select the folder you unzipped the extension in
Note: it works in bing chat main page, and you have to wait for the page content to be loaded, then you will see the word limit change to 25000.
This extension is not affiliated with Microsoft or Bing in any way, and it's not illegal since the Discover button can handle large pages and it's not a violation of the terms of service.
if it caused any problems I can remove it, just let me know.